Tutorial: Simple ATM Machine Program in Java

by eturo

I still remember my teacher in Object-Oriented Programming using Java gave us a Lab Examination (hands-on exam) about how to use classes and methods. The problem he gave us is to create a simple ATM machine program wherein it allows the user to select transactions such as to withdraw, deposit and check or inquiry balance. (see the sample image output dialog below)

 

The program should apply relationship of classes, creating instances or objects and implementation of methods, either overloading or overriding. (see the image below)

Designing:

 

I used BlueJ text editor to design  and create my code. (You can download here.)

Coding:

The Deposit class

Here is the program source code:

public class Deposit extends ATMMachine
{
    static double deposit;
    public void setDeposit(double d)
    {
        deposit = d;
    }
    public static double getDeposit()
    {
        return deposit;
    }
}

The Wihtdraw class

Here is the program source code:

public class Withdraw extends ATMMachine
{
    static double withdraw = 0;   
    public void setWithdraw(double w)
    {
        withdraw = w;
    }
    public static double getWithdraw()
    {
        return withdraw;
    }
}

The Balance Inquiry class

Here is the program source code:

public class BalanceInquiry extends ATMMachine
{
    static double balance = 0;
    public void setBalance(double b)
    {
        balance = b;
    }
    public static double getBalance()
    {
        return balance;
    }   
}

The ATMMachine  class (Note: This is the main program)

Here is the program source code:

import java.util.Scanner;
import java.io.*;
public class ATMMachine
{   
    public static void checkBalance()
    {
        System.out.println("\tYour current balance is " + BalanceInquiry.getBalance());
    }
   
    public static void withdrawMoney()
    {
        if(BalanceInquiry.balance==0)
        {
            System.out.println("\tYour current balance is zero.");
            System.out.println("\tYou cannot withdraw!");
            System.out.println("\tYou need to deposit money first.");
        }
        else if(BalanceInquiry.balance<=500)
        {
            System.out.println("\tYou do not have sufficient money to withdraw");
            System.out.println("\tChecked your balance to see your money in the bank.");
        }
        else if(Withdraw.withdraw > BalanceInquiry.balance)
        {
            System.out.println("\tThe amount you withdraw is greater than to your balance");
            System.out.println("\tPlease check the amount you entered.");
        }
        else
        {
            BalanceInquiry.balance = BalanceInquiry.balance - Withdraw.withdraw;
            System.out.println("\n\tYou withdraw the amount of Php " + Withdraw.withdraw);
        }
    }
                   
    public static void depositMoney()
    {
        System.out.println("\tYou deposited the amount of " + Deposit.getDeposit());
    }
   
    public static void main(String[] args)
    {
        Scanner read = new Scanner(System.in);
        int select = 0;
        int choice = 0;
       
        System.out.println("====================================================");
        System.out.println("\tWelcome to this simple ATM machine");
        System.out.println("====================================================");
        System.out.println();
       
        do
        {try
                {
            do {
               
                    System.out.println("\tPlease select ATM Transactions");
                    System.out.println("\tPress [1] Deposit");
                    System.out.println("\tPress [2] Withdraw");
                    System.out.println("\tPress [3] Balance Inquiry");
                    System.out.println("\tPress [4] Exit");
               
                    System.out.print("\n\tWhat would you like to do? ");
                    select = read.nextInt();
   
                        if(select>4)
                        {
                            System.out.println("\n\tPlease select correct transaction.");
                        }
                        else
                        {
                        switch (select)
                        {
                            case 1:
                                System.out.print("\n\tEnter the amount of money to deposit: ");
                                Deposit.deposit = read.nextDouble();
                                BalanceInquiry.balance = Deposit.deposit + BalanceInquiry.balance;
                                depositMoney();
                                break;
                               
                            case 2:
                               
                                System.out.print("\n\tTo withdraw, make sure that you have sufficient balance in your account.");
                                System.out.println();
                                System.out.print("\tEnter amount of money to withdraw: ");
                                Withdraw.withdraw = read.nextDouble();
                                withdrawMoney();
                                break;
                               
                            case 3:
                                checkBalance();
                                break;
                           
                            default:
                                System.out.print("\n\tTransaction exited.");
                                break;
                               
                        }
                    }               
                          
            }while(select>4);
           
            do {
                try
                {
                    System.out.println("\n\tWould you like to try another transaction?");
                    System.out.println("\n\tPress [1] Yes \n\tPress [2] No");
                    System.out.print("\tEnter choice: ");
                    choice = read.nextInt();
               
                        if(choice>2)
                        {
                            System.out.print("\n\tPlease select correct choice.");
                        }
                    }
                   
                    catch(Exception e)
                    {
                        System.out.println("\tError Input! Please enter a number only.");
                        read = new Scanner(System.in);
                        System.out.println("\tEnter yout choice:");
                        choice = read.nextInt();
                    }
            } while(choice>2);
        }
        catch(Exception e)
                {
                    System.out.println("\tError Input! Please enter a number only.");
                    read = new Scanner(System.in);
                    System.out.println("\tEnter yout choice:");
                    select = read.nextInt();
                }
               
        }while(choice<=1);
       
        System.out.println("\n\tThank you for using this simple ATM Machine.");
    }
}

You can test the program source code above using any text editor for creating Java source codes. Run it and you can see the output. Happy coding...